A multifunction-type vibration actuator and a mobile terminal device capable of decreasing the lowest acoustic resonance frequency and preventing breakage of a coil lead as well as improving acoustic characteristics and preventing sound leaks. A portion near the outer periphery of a diaphragm 3 is bent to form a rising portion 3b extending along an inner periphery 1a of a housing 1 toward an open end thereof. This rising portion 3b serves as a corrugation to decrease the lowest resonance frequency and the amplitude of vibration of which a fulcrum is served by the rising portion 3b is not so large as that of the corrugation. Accordingly, the coil lead of a voice coil 4 is not easily broken. Furthermore, an extending portion 3c is formed to extend outward along a flat surface 1b formed at the open end of a housing 1 from a rising portion 3b. This enlarges the entire radius of the diaphragm 3 and improves the acoustic characteristics. Moreover, by arranging a flat surface 1b of a housing 1 parallel to an extending portion 3c of a diaphragm 3, a gasket can easily be attached.